I wonder what are involved in an encryption key of ds_map_secure_save function. Long story to short, I have two save files encrypted using ds_map_secure_save (as said by the author) from the same computer, one is created before my old HDD fails, and one is after I replaced the drive. OS and motherboard remain the same. However, I can only get the newer file decrypted. So here are the questions: Why do the save files encrypted on the same device have different encryption keys? Was they bound with individual information of the HDD? If HDD info isn't involved, is there any way to decrypt the files? Spoiler: The long story Actually, not one but eight files was created before the HDD fails. They are save files of Ponyvania: Order of Equestria v1.008. The eight old files are kept safe as well as their backup copies. When my old HDD failed, I sent my computer to the computer repair station, then the technicians installed a new HDD and the same OS, without any other things changed. The makers of the two HDDs are different. I installed Ponyvania v1.008, then I tried to load my old 8 save files. No luck. I created a new save file. I tested with different user profiles on the same computer, and all of them can load the file. Then, I reset the computer and reinstalled Ponyvania. The new file can still be opened, meaning that any info of the installation (e.g. installation time) has nothing to do with the encryption. If files cannot be decrypted, they must have decryption key(s) different to the current machine. I've contacted the game author, and he said he used only ds_map_secure_save to encrypt the files, as well as he has removed the feature in newer versions. However, if I can't decrypt the old file (by loading them with the same decryption key) first, they can't be converted to the new format without the use of ds_map_secure_save.